8 



varying in size chiefly according to the time they have been 

 forming. These cubes, though each perfect in itself, form 

 at all angles, and possess no symmetry of arrangement as 

 regards each other, as will be seen by the specimen I 

 produce, which is the growth of over 20 years. It is only 

 under water that the crystals form, for as soon as the 

 surface of the crystal appears above the brine it becomes 

 covered with a saline efflorescence. This efflorescence 

 generally takes the form and appearance of minute cauli- 

 flowers. In the Rajputana saline lakes, the surface upon 

 which the salt crystals form being mud — the salt crystals 

 being taken out every year — each crystal forms separately, 

 as will be seen in the specimens I produce from Pachbadra, 

 called " mud salt." 



As rock salt if exposed to the weather dissolves, unless 

 great care is taken the crystals soon lose all their sharp 

 angles and form a rounded mass. To prevent this dissolving 

 of the angles it is weU to keep the rock salt either in a very 

 dry place or in a saturated solution of brine, it being a 

 common saying in Cheshire, that " the best place to keep 

 rock salt is in brine." I wish this fact to be borne in mind, 

 for it will explain the phenomenon of least solution of rock 

 salt taking place at the brine pumping stations of Cheshire ; 

 a fact which puzzles many, and which has led to the pro- 

 pounding of many curious and unscientific theories. 



Saturated brine left perfectly motionless, but exposed to 

 the atmosphere, creeps by capillary attraction, and forms a 

 saline incrustation or efflorescence. 



II. — Water descending hy gravitation and loassing over 

 beds of salt in its course to a lower level. 



This is a case of water in motion passing from a higher to 

 a lower level, and on its way flowing over beds of salt. 



In several parts of the world the beds of rock salt lie 

 upon the surface or stand out as hills exposed to the 



